The chapter starts with an old man with a tengu mask named Sakonji Urokodaki receiving a letter from a crow. The letter sent by Giyu Tomioka states that a young boy whose family that was slaughtered by a Demon is on his way to meet the old man, and that the boy's sister has turned into a Demon, but Tomioka believes that she will not harm humans. Tomioka also observed that the boy possesses the same ability as Urokodaki, which is that they both have a particularly good sense of smell. Tomioka also feels that the boy might make a break through and beseeches Urokodaki to allow the boy to be his successor.
The flashback ends and Urokodaki is now looking at Tanjiro who is about to finish off the Head Demon with a small knife. Tanjiro notes that he had not noticed Urokodaki's presence at all as his footsteps were so light. Tanjiro then asks, how would one go about killing a Demon, to which Urokodaki replies that he should figure it out himself.
Tanjiro saw a rock nearby and decided that he could use the rock to bash the Demon's skull repeatedly till it dies. However, he realizes that the Demon would also suffer. Urokodaki, upon seeing the Tanjiro's hesitation, could also smell the overflowing empathy and kindness off Tanjiro. He also berates Tomioka in his mind, telling him that this boy isn't the suitable candidate Tomioka thinks he is.
As Tanjiro was still hesitating, the first rays of sun appeared and burned the Demon to ashes, causing Tanjiro to realize why Nezuko dislikes the sun so much. Meanwhile, Urokodaki had already given the victims a proper burial.
The man with the tengu mask introduces himself as Urokodaki Sakonji and before Tanjiro could properly introduce himself and his sister, Urokodaki asks Tanjiro what will he do if his sister eats a human being. As Tanjiro pauses before answering, Urokodaki slaps him and reprimands him for being too hesitant. He tells Tanjiro that in the event his sister eats a human being, he should kill her and then kill himself. That is the kind of resolve that Tanjiro needs if he wants to bring along his sister who has turned into a Demon on the journey. Tanjiro replies that he understands, to which Urokodaki tells him that he wants to test him, and to bring Nezuko and follow him.
Urokodaki was swift and Tanjiro had a hard time chasing after him. As he is running, Tanjiro feels sorry for Nezuko that is being jostled around in the basket. He recalls that Nezuko has always been patiently enduring throughout her whole life. For the sake of their siblings, Nezuko had refused to buy new clothes in order to buy more food for them instead. Tanjiro firmly decides that he will turn her back into a human and give everything to her to make up for the things he is unable to do for his now deceased siblings.
They soon reached a hut and Tanjiro breathlessly asks whether he has passed the test. Urokodaki tells him that the test has only just begun, and for him to follow Urokodaki up the mountain. Upon hearing those words, Tanjiro became dumbfounded as he thought that the test was to catch up to the extremely fast Urokodaki.
Soon afterwards, they both head up into the mountains. Tanjiro feels that his legs are so tired that he is unable to move them, and that his head is spinning like crazy. Urokodaki tells him that the test is for Tanjiro to reach the bottom of the mountain to where his house is, and unlike with the Head Demon, he will not wait till dawn, and subsequently leaves.
Tanjiro was surprised that the test was that simple. As he has a good sense of smell, and he still remembers what Urokodaki smells like, he feels that the test will be a breeze. Before Tanjiro could even take another step, his foot gets caught in a trap, launching small rocks towards him. He then falls into a dug out hole, and then, after crawling out, into another trap that launches a log which hits him from behind.
Tanjiro then realizes that if he keeps getting caught in the traps, he would not be able to reach the foot of the mountain by dawn. Moreover, the air in this mountain is thinner than where he had lived before, causing him to have breathing difficulties. Feeling despair, he wonders whether he could make it back in time, but he then steadies himself and tells himself that he must make it back. By adjusting his breathing and concentrating, he could smell out the distinctly different human traps. Even so, he is not agile enough to avoid all traps.
Meanwhile, by the foot of the mountain, Urokodaki places a blanket over the sleeping Nezuko. He suddenly hears some noise by his door. The sliding door opens to reveal a very battered Tanjiro panting heavily. As he slumps down to the ground, Tanjiro slowly voices out the words, "I...have...returned...".
As the morning sun begins to rise, Urokodaki tells Tanjiro that he has now acknowledged him as his student.
Characters in Order of Appearance
- Tanjiro realizes demons burn and turn into ash when exposed to sunlight
- Urokodaki challenges Tanjiro to determine if he'll train him